The present invention relates to a process for forming fiber reinforced rods and more particularly relates to a method for making high modulus, high strength, low density slender tapered solid composite rods suitable for use as fishing rods and the like.
Typically, present day high quality fiber glass fly rods are hollow and are constructed by wrapping a resin-impregnated fiber glass cloth over a tapered, removable steel mandrel. After oven curing, the mandrels are removed preparatory to rod finishing. This type of hollow construction is employed in order to reduce rod weight while maintaining appropriate section stiffness. As a result however, the rod diameter is relatively large and tip windage losses during casting are significant.
With the advent of newer, high specific modulus fibers such as boron and graphite, the concept of a cross-sectionally solid rod having acceptable section stiffness without an appreciable weight penalty is feasible. Such a rod would possess both minimum tip windage losses as well as maximum structural integrity against lateral loading.
Although the potential advantages of modern day materials is thus recognized, the problems apparent in utilizing them have remained for solution. While rod construction via tape lay-up may be accomplished in several ways, significant problems arise in the curing of a solid composite green rod since, during this time, it is difficult to restrain the filaments from wandering. The end result can be the occurrence of nonconcentric rod ends, local bulging and/or warping. While it may be speculated that matched dye molding or tapered tube molding would likely solve all of these problems, the large expense due to large L/D ratios, the compound tapers employed in most rods and the large number of different models usually manufactured, renders this technique unattractive.